One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of determining when it's a good idea to plant larkspur is to check out the USDA zone info for Green River.

Planting Calendar for Larkspur

Frost tolerance for larkspur:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Larkspur are very cold tolerant which means that you can start planting them much earlier than other plants that might not handle the cold.

The earliest that you can plant larkspur in Green River is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant larkspur and expect a good harvest is probably August. If you wait any later than that and your larkspur may not have a chance to really do well. Starting your larkspur indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Green River. It might get as low as -25°F during the coldest months of winter.

Keep in mind that USDA zone info for Green River may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Green River you get a frost after May 15 be ready to protect your larkspur if you have a late frost.

USDA Zone Info for Green River

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Green River

You may be interested in your other planting guides for Green River.